This invention relates to a device for use in conjunction with a well test tool of the type disclosed in U.S. Pat. No. 4,373,380, and has for one of its objectives to increase the utility of the patented test tool.
In the patented test tool, an axially spaced pair of annular resilient rubber or rubber-like seals are held in metal containment rings to form unitized seal assemblies. The two resilient seals are first energized responsive to the application of energizing fluid pressure in the tool to compress them axially and thereby expand them radially into fluid sealing engagement with a sleeve in surrounding relationship to the test tool.
While so energized, the two seals are subjected to test pressure at a required magnitude delivered by pressurized test fluid in the tool on a different flow path.
When the test tool seals are de-energized following completion of a test, they return to their normal relaxed shapes due to their elastic memories. If the surrounding rigid sleeve component, such as a well head housing or well casing section, possesses a wear deformity, such as a groove or key seat in its bore caused by the action of drilling pipe or the like, the test seal assemblies on the patented tool will afford no indication or measurement of such wear deformity through the elastic seal element or the associated metal containment elements which may not be forced by fluid pressure into an adjacent wear deformity in the surrounding sleeve.
In accordance with the present invention, one of the test tool seal assemblies is removed from the tool and in its place the wear deformity detection and measurement device of this invention is installed. The device has the exact configuration of the removed seal assembly and occupies the same space on the test tool. In lieu of the resilient rubber-like test seal element, the device according to the invention has a contained element formed of lead or a similar alloy or non-metallic composition which lacks elasticity or resiliency and has virtually no elastic memory. This component is held in assembled relationship with substantially rigid containment rings designed to facilitate removal and replacement of the non-resilient lead or lead-like component following its use for detecting, locating and measuring an existing wear deformity, such as a groove in a surrounding casing or other sleeve.
When the assembly, according to the invention, while mounted on the test tool is energized by the application of fluid pressure, in the same manner that the resilient test seal is normally energized, the non-elastic lead or lead-like element will be forced by pressure to flow into the wear deformity of the surrounding rigid sleeve, and following removal of the tool from such sleeve, the non-resilient seal simulating element will retain on its exterior a permanent bulge or protrusion precisely indicative of the shape and size of the wear-induced groove or other recess in the surrounding rigid sleeve. The permanently deformed non-elastic detection and measuring element of the invention can have its deformity or protrusion precisely measured to reveal the condition of the worn surrounding sleeve, for the purpose of determining the future usefulness, if any, of such sleeve, whether a sub-sea well head housing, a well casing section or the like.
Other features and advantages of the invention will become apparent to those skilled in the art during the course of the following description.